Cushing's Syndrome in Dogs
Cushing’s syndrome, also called hyperadrenocorticism, occurs when your dog’s adrenal glands produce too much cortisol, an essential hormone released in response to stress. While cortisol is needed for normal bodily functions, too much cortisol can cause serious health consequences.
The majority of of all Cushing’s syndrome cases (80% to 85%) are caused by a small, benign tumor located in the pituitary gland, found at the base of the brain. This noncancerous tumor produces a hormone that stimulates the adrenal glands to enlarge and produce too much cortisol.
In the remaining 15% to 20% of dogs with Cushing’s, the cause is a malignant tumor affecting one of the adrenal glands, causing the gland to produce too much cortisol.
In some cases, Cushing’s syndrome can be caused by the long-term use of steroid medications (e.g. prednisone) to treat many conditions such as allergies, inflammation, and autoimmune disease.
Cushing’s disorder can be hard to spot. The symptoms are variable and can be mistaken for other common problems. Often, the symptoms are erroneously thought of as old age.
If your dog has Cushing’s syndrome, you may notice any of the following symptoms:
- Increased thirst
- Increased urination
- Increased appetite
- A pot-bellied appearance
- Loss of hair along the back, near the tail
- Darkening of the skin
- Recurrent skin and urinary tract infections
- Increased panting
Determining if your best friend has Cushing’s can be tricky as there isn’t one test that can absolutely diagnose it. Your veterinarian will take a complete history of your dog and perform a thorough physical exam.
Some of the diagnostic tests they may recommend are:
- Chemistry tests to evaluate kidney, liver, and pancreatic function, as well as sugar levels
- A complete blood count to rule out blood-related conditions
- Electrolyte tests to ensure your pet isn’t dehydrated or suffering from an electrolyte imbalance
- Urine tests to screen for urinary tract infection and other disease, and to evaluate the ability of the kidneys to concentrate urine
- Urine tests to measure the amount of cortisol in the urine
- A thyroid test to determine if the thyroid gland is producing too little thyroid hormone
- Cortisol tests to evaluate your dog’s blood cortisol levels
- Blood pressure measurement
Additionally, though less commonly, your veterinarian may recommend the following tests:
- An ECG to screen for an abnormal heart rhythm, which may indicate underlying heart disease
- Antibody tests to identify if your pet has been exposed to tick-related